Dust deflector



P 1936- G. s. KELLEY DUST DEFLECTOR Filed Nov. 29, 1935 M m a m N m m m w 10 A M H a m Patented Sept. 29, 1936 UNITED STATES PATENT} OFFICE 2,055,768 DUST nErLEc'roR Application November 29, 1935, Serial No. 52,131

3 Claims.

This invention relates to dust deflectors, and more particularly to a dust deflectoradapted for'use in connection with rock drilling apparatus equipped with means for ejecting the dust from the hole being drilled.

In its preferred form the dust deflector consists of a single member adapted to be freely inserted in the entrance of a drill hole to convey the cuttings therefrom, and is so devised as to allow the cutting implement to pass readily therethrough for inserting it into and withdrawing it from the drill hole.

One object of the invention is to assure the correct operative relationship of the dust deflector with respect to the drill hole and the implement forming the hole. 7

Another object is to enable the dust deflector to be expeditiously moved into and held in the correct relationship with respect to the source of dust and,

A further object is to simplify the construction and, therefore, minimize the cost of manufacturing of devices of this character.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawing accompanying this specification and in which similar reference numerals refer to similar-parts, g

Figure 1 is an elevation, in section, of a dust deflector constructed in accordance with the practice of the invention and a rock drilling mechanism, the latter being partly broken away Figure 2 is a transverse view taken through the deflector on the line 22 in Figure 1, and

Figure 3 is an elevation, in section, of a modified form of the invention.

Referring more particularly to the drawing and at first to the form of the invention illustrated in Figures 1 and 2, designates a dust deflector constructed in accordance with the practice of the invention, and 2| a drill hole in the rock 22 into which the dust deflector 20 extends.

The drilling mechanism whereby the drill hole 2| is formed comprises a rock drill 23 of which only so much is shown as will illustrate the invention for actuating a working implement 24 extending through the dust deflector 20. The working implement is illustrated as having an enlarged cutting bit 25 at and near its rear end are lugs 26 to interlock with chuck mechanism 21 in the rock drill 23 to prevent ejection of the working implement from the rock drill and to prevent rotation of the working implement with respect to the chuck mechanism.

The working implement is hollow throughout its length to provide .a channel through which motivating fluid maybe introduced either periodically or constantly from the rock drill 23 into 'the drillhole for raising the cuttings.

ance with the practice of the invention, preferably consists of a single member or casing having a main body portion 28 of which the lower end 29 extends, into the drill hole and is preferably of only smaller, diameter than the bit 25 of the starting drill steel so that some space will exist between its periphery and the wall of the drill hole. v g 7 The mainbody portion of the casing is hollow and the passage 30 which extends entirely therethrough serves to convey dust through its lower end 3| and atmospheric air through its upper end 32 to an intermediate portion of thepassage 30 or, more particularly, to an outlet'opening 33 defined by a lateral projection 34 on the, casing and located intermediate its ends. Preferably the projection 34 and, therefore, the outlet opening 33 arelocated near the uppermost portion of the casing and a baffle 35, depending in the direction of the lowermost end 3| of the passage 30, is arranged in the projection 34 near the passage 30. I I i V The bafile thus cooperates with the adjacent portion of the passage 30jto determine the dis- 1 Eli The dust deflector 20, constructed in accord- 'tance which the atmospheric air must travel through the passage 30 before entering the outlet opening 33. In this way is assured the admission of a sufficient volume of atmospheric air into the casing to effect an air seal between the working implement and the upper end of the casing for destroying the energy of the dust particles rising through the passage 30, and thereby prevent ejection of cuttings from the passage 30 to the atmosphere. The atmospheric air thus entering the casing serves to direct the cuttings into the outlet opening 33 whence they may pass through a conduit 36 to a suitable evacuating device, for example a blower (not shown) but which may be connected to the conduit 36 to evacuate the drill hole.

The casing 20 is more particularly adapted for down-hole drilling and the portion 3| is of smaller diameter than the remaining portion of the passage 30. The front end 29 of the casing is accordingly also of reduced diameter and at its rear end is an external shoulder 31 which may rest on the rock to limit the distance which the casing may extend into the drill hole.

Referring now to the modified form of the invention illustrated in Figure 3, the dust deflector, designated 38, diifers from that previously described principally in that the extension 39 defining the outlet opening 40 for the passage 30 is arranged at an acute angle with respect to the main body portion 28. The dust deflector shown in this figure is more particularly adapted for use in connection with horizontal drill holes and, by arranging the extension 38 in the angular position described, the weight of the connection 38 suspended from the projection 38 will tend to tilt the dust deflector in the drill hole and thereby cause the end 29 of the deflector to be pressed into tight frictional engagement with the wall of the drill hole to assure its retention in the correct operative position.

In practice, the dust deflector is passed over the shank end of the working implement employed for starting the drill hole and of which the bit is necessarily of greater diameter than the end 29 of the deflector in order to' permit the entrance of such end into the drill hole. The working implement in then inserted in the chuck mechanism of the rock drill after which drilling may proceed.

During the starting of the drill hole, and assuming the rock drill to be of the manually supported and guided type, the deflector may be maintained in sufficiently close proximity to the cutting bit to assure the effective removal of the dust, as rapidly as formed, by holding it firmly against the gage of the cutting bit by pressure of the foot.

As the working implement penetrates the rock the leading end of the deflector enters the drill hole until the shoulder 31 encounters the rock 22. The working implement will then continue to advance into the rock until it reaches the limit of its extent. Both the working implement and the dust deflector are then withdrawn and the dust deflector is removed from the rear end of the working implement and again inserted into the drill hole.

Thereafter, successive working implements may be inserted in the rock drill in the customary manner and, by reason of the thin wall of the deflector, may pass readily through the passage 30 to enter them into and withdraw them from the drill hole. This operation may be repeated as often as necessary to complete a hole of the desired depth, and during such drilling and with the evacuator in operation the dust will be drawn from the bottom of the hole and at the same time an envelope of atmospheric air will enter the portion 32. These counter streams of dust and atmospheric air join and pass through the passage 33 and the connection 36 to the evacuator. The diameter of the portion 32 of the passage 30 and the distance from the outer end of said portion to the inner end of the bafile may be suitably proportioned to assure an air seal at this point of suflicient value to preclude the ejection of dust to the atmosphere. By thus drawing atmospheric air into the deflector such small particles of dust as may be strewn on the rock face upon which the operator moves will also be drawn through the deflector through the evacuator and will be removed from the drilling site.

The present invention has been found to be a highly eflicient device for effecting the positive and efficient removal of dust from both the drill hole and the vicinity of the drilling operation. As will be readily appreciated, it is of simple construction and so designed that it may be conveniently and cheaply manufactured.

I claim:

1. A dust deflector adapted to be inserted in a drill hole and havingapassage to receive counter currents of dust and atmospheric air and an outlet opening for the passage intermediate the ends of the deflector, and a baffle in the casing adjacent the passage and partly overlying the outlet opening.

2. A dust deflector comprising a casing having a reduced end to extend into a drill hole and a bore extending therethrough to receive counter currents of dust and atmospheric air, a lateral extension on the casing having a passage forming an outlet opening for the bore, and a bafile at the juncture of the bore and the passage.

3. A dust deflector comprising a casing adapted to extend into a drill hole, an integral lateral projection intermediate the ends of the member and having a passage, said casing having a passage extending therethrough to convey counter currents of air and dust to the passage, and a bafile in the casing forming bounding surfaces for both passages.

GEORGE S. KELLEY. 

